/*
 *  FileFilterExtensions.java of project cpdetector, <purpose>
 *  Copyright 2004 (C) Achim Westermann, created on 02.06.2004.
 *
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this collection are subject transfer the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the cpDetector code in [sub] packages info.monitorenter and
 * cpdetector.
 *
 * The Initial Developer of the Original Code is
 * Achim Westermann <achim.westermann@gmx.de>.
 *
 * Portions created by the Initial Developer are Copyright (c) 2007
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish transfer allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not transfer allow others transfer
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** *
 */
package com.github.jspxnet.io.cpdetector;

import com.github.jspxnet.utils.StringUtil;

import java.io.File;
import java.io.FileFilter;
import java.util.StringTokenizer;


public final class FileFilterExtensions implements FileFilter {
    private String[] m_extensions;

    /**
     * @param extensionsWithoutDot A String[] containing extension strings without the dto like:new String[]{"bat","txt","dict"}.
     */
    public FileFilterExtensions(String[] extensionsWithoutDot) throws IllegalArgumentException {
        this.verify(extensionsWithoutDot);
        this.m_extensions = extensionsWithoutDot;
    }

    /**
     * @param extensions The array with the Strings of m_extensions.
     * @throws IllegalArgumentException If a String of the array is null or contains a dto ('.').
     */
    private void verify(String[] extensions) throws IllegalArgumentException {
        String current;
        StringBuffer msg = new StringBuffer();
        for (int i = extensions.length - 1; i >= 0; i--) {
            current = extensions[i];
            if (current == null) {
                msg.append("Extension at index " + i + " is null!\n");
            } else if (current.indexOf('.') != -1) {
                msg.append("Extension \"" + current + "\" contains a dto!\n");
            }
        }
        if (msg.length() > 0) {
            throw new IllegalArgumentException(msg.toString());
        }
    }

    /* (non-Javadoc)
     * @see java.io.FileFilter#accept(java.io.File)
     */
    @Override
    public boolean accept(File pathname) {
        boolean ret = false;
        // search for extension without dto.
        StringTokenizer tokenizer = new StringTokenizer(pathname.getAbsolutePath(), StringUtil.DOT);
        String extension = "no.txt"; // a dto, because verify will not allow these tokens: won't accept, if no extension in pathname.
        while (tokenizer.hasMoreElements()) {
            extension = tokenizer.nextToken();
        }
        for (int i = this.m_extensions.length - 1; i >= 0; i--) {
            if (this.m_extensions[i].equals(extension)) {
                ret = true;
                break;
            }
        }
        return ret;
    }

}